This invention relates to a system and components thereof for collecting and locally analyzing fluid specimens, e.g., body fluids such as urine.
Devices for collecting and locally analyzing body fluids have been described in the patent literature, as exemplified by U.S. Pat. No. 5,403,551. Such devices may be used, for example, by employers to screen employee applicants for illegal drug use. As noted in U.S. Pat. No. 5,403,551, it is desirable for drug screening tests to be locally performed, i.e., at the collection site, for the purpose of quickly determining on a qualitative basis whether specific drugs are present in a fluid specimen, typically, urine. If the results of the screening test are positive, a more complete quantitative analysis is subsequently performed, typically, at a remote laboratory site. Inasmuch as it is extremely important to positively correlate the specimen with the person being tested, U.S. Pat. No. 5,403,551, describes an assaying device that minimizes possible contamination of the specimen after the specimen is first collected. More particularly, U.S. Pat. No. 5,403,551 describes a device which functions to both collect and locally analyze a specimen. The device comprises a container for collecting and storing the specimen, a cap for sealing the container, and an assay means attached to the container for qualitatively analyzing a portion of the specimen. The assay means is described as using a plurality of latex/antibody chromatograph strips. Since the specimen does not have to be transferred out of the container for qualitative testing, if the initial test produces a positive result, the entire device containing the specimen can then be shipped to a laboratory for quantitative analysis.
The aforementioned Lappe applications variously describe machine readable assaying systems employing test or assaying cards bearing test or analysis strips thereon. The strips are configured such that when wetted by a fluid, they will react to visually indicate the presence of certain detectable substances in the fluid. The format of the visual indications can be of many different types capable of being machine read by a suitable reading apparatus.
The present invention is directed to a method and apparatus for collecting a fluid specimen and locally analyzing the specimen to qualitatively detect specified chemical components therein. More particularly, the invention is directed to such an apparatus which provides machine readable test results for facilitating the data collection and reporting of the results.
Apparatus in accordance with the invention includes an assaying device comprised of a cup for collecting a fluid specimen and a cap carrying at least one test strip for visually reacting to one or more specified chemical components in the specimen. The assaying device is preferably configured to interact with a reader device capable of reading the reaction of the test strip to produce an electronic data output.
One example of a test strip suitable for use with embodiments of the invention comprises membrane strips pre-coated with drug protein conjugates deposited on defined bands of the strip. Such strips are commercially available as the InstaCheck Multi-Drug Screen Panel manufactured by Forefront Diagnostics, Inc. of Laguna Hills, Calif.
In accordance with a preferred embodiment of the present invention, the assaying device carries one or more test strips which collectively test for multiple characteristics of the fluid specimen including the presence of specific chemical components at concentrations above threshold levels, the authenticity of the specimen (as, for example, whether it is freshly voided urine), and whether or not the specimen has been adulterated.
A preferred assaying device in accordance with the invention includes an open cup defining an interior volume for accommodating a fluid specimen and an attachable cap configured for mounting on the cup to seal the interior volume. The cap carries at least one test strip and an aliquot delivery mechanism actuatable to wet the test strip with an aliquot derived from the fluid specimen. In a preferred embodiment of the invention, the aliquot delivery mechanism comprises a pump in the form of a plunger for forcing an aliquot of the fluid specimen onto the test strip. The plunger can be actuated either manually or automatically, e.g., by a piston controlled by a compatible reader device.
In accordance with the preferred embodiment, the aliquot delivery mechanism includes first and second concentric tubular walls descending from the cap into the cup. A passageway is defined between the tubular walls having an inlet at its lower end for contacting the specimen in the cup and an outlet at its upper end for delivering an aliquot onto the test strip.
In accordance with a significant feature of the preferred embodiment, the descending tubular walls and interior cup floor are cooperatively configured to isolate a portion of the specimen when the cap is installed onto the cup. The plunger acts on this isolated portion to force a small part thereof, i.e., an aliquot, through the passageway onto the test strip.
Tests strips used in preferred embodiments of the invention provide a visual reaction to chemical components having a concentration in the aliquot greater than a threshold concentration. Preferably, each test strip functions so that a negative test result for one or more components causes a multiple number of visually discernable discrete bands to appear on the strip. The presence of a single component in excess of a threshold suppresses the development of at least one of the bands. Therefore, the absence of a visually discernable band indicates a positive test result for a particular chemical component associated with that band.
The cap is preferably configured with one or more compartments, each for accommodating a different test strip. The passageway, which may comprise multiple branches, extends to the compartment for delivering an aliquot thereto. The cap preferably also defines one or more catch basins to catch any excess fluid delivered by the aliquot delivery mechanism to the test strip.
The cap is preferably also configured to define a transparent area or window located relative to the test strip compartment to enable the strip visual reaction to be read by a machine, e.g., a digital camera and image processor, and/or a human.
In accordance with a preferred embodiment, the cap and cup are provided with cooperating coupling means (e.g., mating threads or a bayonet mount) configured to seal the cup interior volume when key exterior portions of the cap and cup are physically aligned. More particularly, when the cap is fully installed on the cup, a key external portion of the cap, e.g., a flat slotted area, aligns relative to a key external portion of the cup. When these key external portions align, the aforementioned interior tubular walls form an interior chamber for isolating the aforementioned portion of the specimen.
The exterior of the cap and cup preferably have an irregular periphery to facilitate easy manual handling. The periphery is preferably also shaped to assure its particular orientation in a receptacle of a compatible reader device. When inserted in the receptacle, the cap is properly positioned to enable the test strip in the cap to be read by an imager, e.g. a digital camera, housed in the reader device.
A preferred reader device in accordance with the invention includes a microprocessor based controller for actuating the aliquot delivery mechanism of an assaying device placed in the reader device receptacle. More particularly, the reader device preferably includes an actuatable piston for pressing the delivery mechanism plunger to deliver an aliquot to the test strip. Preferably, the piston remains engaged with the assaying device for the duration of the test (typically, up to eight minutes) to prevent a person from substituting specimens during the course of a test.
The reader device preferably includes a camera and image processor controlled by the controller for viewing the test strip of an assaying device to produce a positive or negative test result for the specimen contained therein. The test result data, along with identification data read from a label carried by the assaying device, can then be stored or communicated, e.g., via a modem.
Embodiments of the present invention are used primarily to perform local on-site screening while preserving an uncontaminated specimen for further analysis if necessary. That is, in typical use, embodiments of the present invention function to perform a qualitative analysis on an aliquot of the specimen to screen for negative results. If a negative result is not achieved, then the sealed assaying device containing the remaining uncontaminated specimen is typically shipped to a remote site for further analysis.